In the grand scheme of things, there is a lot of information out there about what it takes to be a great boss. The problem is that much of it gets lost in the noise as we become mired in overly complicated, insufficiently realistic analyses and advice.
But if you think about beloved bosses, the ones who are able to generate the greatest business results, bring out the best in people and affect lives long after the working relationship is over, you will see that they share an important trait in common. Simply put, they are givers not takers. They are adults, not children. They are professionally, intellectually and emotionally mature. Sounds easy right? In theory yes, but in practice, no.
Because you can't fast-forward the human development process, if there has been a slow down at any point in the road. It takes time to learn, it takes time to grow, and it takes time to undo whatever stands in the way of someone's ability to mature naturally over time. A management course won't do it, nor will a book, not if the person who aspires to be a great boss isn't open and willing to grow up and go without resistance through the phases that life has in store.